Superconducting InGaAs junction field-effect transistors with Nb electrodes

Abstract

We describe the design, fabrication, and characterization of superconducting In0.47Ga0.53As junction field-effect transistors (JFETs) with Nb source and drain electrodes. In 0.47Ga0.53As has the advantage of combining large coherence length and high Schottky barrier transmission, making it a very attractive material on which to base superconducting FETs. At large voltages these devices behave as normal FETs in either enhancement or depletion modes, while at small voltages they act as Josephson junctions or super-Schottky diodes. Both normal and super- currents are controlled by the gate.